Electrodermal positioning device and process of making same

ABSTRACT

A template has a flexible sheet with a fixed dimensional array V 1  -V 6  positioned in a specific size configuration appropriate for standard electrocardiographic recording. The distance between V 1  and V 2  is 2.00 inches±0.56 inches, and the distance between V 2  and V 4  is 3.5 inches±1.00 inch, with V 3  located substantially midway between V 2  and V 4 , and V 5  is equidistant between V 4  and V 6 .

RELATED U.S. APPLICATION

This application is a continuation of application Ser. No. 08/783,904,filed Jan. 16, 1997, now U.S. Pat. No. 5,865,741, issued Feb. 2, 1999,which is a continuation-in-part of application Ser. No. 08/508,928,filed Jul. 28, 1995, now abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a disposable medical device for use whenemploying electrical signals to monitor or stimulate various parts ofthe body. More particularly, the present invention involves a templatedevice for assistance in establishing electrical connection to apatient's skin. The template can be used in conjunction with a pluralityof electrode connectors or electrodeless connectors and anelectrocardiological measuring apparatus.

2. Description of the Prior Art

Prior art medical electrodes generally are combination structuresincluding a metallic or otherwise conductive support member to which anelectric wire from an assorted apparatus may be attached. Generally,electrocardiograms sometimes referred to as an EKG or ECG have ten cableleads which attach to various points on the upper and mid-torso of apatient to measure and analyze cardiac data.

Of primary concern when preparing for an electrocardiogram is accurateplacement of the electrodes. The person responsible for attaching theelectrodes and lead wires ("leads") of the EKG often has problems inattaching these multiple leads to the patient because the lead wires maytangle with one another or, in the case of suction-type electrodes, maybecome detached before or after they are all connected. Accuratelyplacing and securing a large number of leads can be difficult and timeconsuming and requires the knowledge of a skilled technician orphysician.

Periodic electrocardiograms can provide a cardiographic profile of apatient for early detection and diagnosis of cardiovascular diseases.For purposes of providing an accurate profile, it is important not onlythat the electrocardiogram be taken with sensors affixed accurately, butthat the sensors are placed at the same location on the patient as forthe previous electrocardiograms. The accuracy of the reproducibleresults is critical so that a series of electrocardiograms can becompared, between testing episodes, to provide a continuing profile of apatient for diagnosis and treatment of heart disease.

A full screen, ten electrode (twelve lead) electrocardiograph providesthe most accurate picture for recognizing ischemic electrocardiographicchanges. However, in urgent situations, including thoseelectrocardiograms taken during an acute symptomatic episode of acardiac patient, only two to four electrodes may be attached to thepatient. Therefore, it would be advantageous and desirable to have adevice which enables more leads to be accurately placed and quicklysecured during an acute symptomatic episode.

On the other hand it may be necessary to quickly remove certain or allof the chest leads of the EKG when a patient is experiencing anotherheart attack in order to administer CPR, to massage the heart,administer drugs or apply electrical defibrillation paddles.Accordingly, valuable seconds are often lost in removing the chest leadsof the EKG device in order to administer aid to the patient.

U.S. Pat. No. 4,328,814 to Arkans teaches a plurality of electrodesarranged in a strip. Each electrode has a conductive lead which runs toa single junction connector having one cable leading to the EKG device.This device is designed for an adult patient so that patients havinglarger or smaller torsos will have difficulty in using the devicebecause the electrodes cannot be easily adjusted to accommodate asmaller or larger torso.

U.S. Pat. No. 4,353,372 to Ager discloses a plurality of electrodeswhich plug into a junction box connected to an EKG machine. Each of theelectrodes includes wires molded into a central cable system which joinsthe junction box. This device does not include means for quicklyattaching or removing the electrodes. For example, in an emergencysituation if the electrodes must be removed quickly, the junction boxmust be disconnected first and then each of the electrodes must bedetached. Although each electrode has a wire lead from the main moldedcable, which may permit some adjustment in the placement of theelectrodes on the upper portion of a human torso, the device is notentirely adequate for large adults or very small children because of thelimited adjustment of each electrode.

U.S. Pat. No. 4,608,987 to Mills relate to a vest-like garment having aplurality of apertures adapted for receiving associated electrodes.However, the vest is not tailored for a specific patient and proper fitis provided by adjustable straps which may be secured by VELCROmaterial. Therefore, there is no assurance that the electrodes areplaced at the same anatomical location upon reuse with the same patient.

U.S. Pat. No. 3,910,260 describes telephonic units for transmitting EKGsignals to ECG receiving equipment which could be at a hospital or aphysician's office. The transmission may take place in emergencyvehicles where prior medical history may not be readily available. Inorder to obtain meaningful and reliable data ECG signals are necessaryfor the care providers. None of the prior art devices have disclosed alow cost solution for obtaining repeatable placement of sensors foraccurate and readable ECG signals in the field by unskilled individuals.

U.S. Pat. No. 4,583,549 to Manoli relates to an ECG electrode pad havinga flexible non-conductive pad provided with a plurality of electrodes.In this patent, the electrodes are positioned at various anatomicallydefined positions on the chest wall. Although different size pads arecontemplated, this patent lacks any teaching or suggestion of how thesizes are dimensioned, how they would be determined, or even how apatient would be fitted with the proper size.

Because of the inadequacies of prior art devices there is a need for asystem which prevents EKG electrode leads from being entangled; providesquick removal of some of the electrodes while leaving the remainingelectrodes in position when it is necessary to administer aid to apatient having a heart attack; provides accurate repeatable placement ofelectrodes at substantially the same anatomical location; accurately andrepeatedly obtains signals from body electrodes by efficient andeffective electrical transmission; may be attached by unskilled persons;and may be available in various sizes to accommodate to fit the patient.

SUMMARY OF THE INVENTION

The present invention, in one aspect involves a disposablenon-conducting flexible sheet having a predetermined dimensional array.The flexible sheet serves as a template for aligning connectors, eitherof the electrode type or electrodeless type, on the chest of a patientfor transmitting (receiving or sending) electrical impulses.

More particularly, this aspect of the invention relates to a disposabletemplate comprising a flexible non-conductive sheet having apredetermined dimensional array V₁ -V₆. The dimensional array is sizedsuch that V₁ and V₂ are positioned approximately on either side of thesternum at the fourth intercostal space and array V₃ is positionedmidway between V₂ and V₄. V₅ is equidistant between V₄ and V₆. Thedistance between V₁ and V₂ is about 2.00 inches±0.56 inches, i.e., V₁ is1.00 inch±0.28 inches to the right and V₂ is 1.00 inch±0.28 inches tothe left, measured equidistantly from the centerline of the sternum. Thedistance between V₂ and V₄ is about 3.5 inches±1.00 inch, and V₃ islocated substantially midway between V₂ and V₄.

In another aspect of the invention, the flexible non-conductive sheet isprovided in a plurality of sizes, with each size having arrays V₁, V₂,V₃ and V₄ at substantially the same locations and having arrays V₅ andV₆ at different locations depending on size. In this regard, thelocations of V₅ and V₆ are based on a measured distance between amidclavicular line and a midaxillary line on the chest of the patient.

In yet another aspect of the present invention, the dimensional array onthe flexible non-conductive sheet is provided with cutouts. The templateis placed on the patient's chest and then conventional electrodes can bepositioned in the cutouts.

In still another aspect of the present invention, the template can beprovided with a plurality of conventional tab electrodes affixed ontheir top sides to the flexible sheet to be placed against the patient'schest. The electrodes are positioned at the predetermined dimensionalarray. Small cutouts, or openings, in the template expose the electrodetabs for attaching lead wire clips.

In yet another aspect of the invention, top sides of individualelectrodes are lightly affixed to the flexible sheet of material, alsoat the a predetermined dimensional array. The sheet is placed on thepatient's chest and then peeled away, leaving the electrodes properlylocated on the chest.

In still another aspect of invention, disclosed is a method of sizing apatient for fitting a template having a flexible sheet with a fixeddimensional array V₁ -V₆ positioned in a specific size configurationappropriate for standard electrocardiographic recording, with thedistance between V₁ and V₂ being 2.00 inches±0.56 inches, and thedistance between V₂ and V₄ being 3.5 inches±1.00 inch, with V₃ locatedsubstantially midway between V₂ and V₄, and V₅ being equidistant betweenV₄ and V₆. The method comprises the steps of measuring the distancebetween the midclavicular line and a midaxillary line on the chest ofthe patient, and selecting a template size based on the measureddistance.

These and other objects, aspects, features and advantages of the presentinvention will become apparent from the following detailed descriptionof the preferred embodiments taken in conjunction with the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a preferred template device of the present inventionprovided with end sensors for attachment to the torso of a patient.

FIG. 2 shows a portion of the device illustrated in FIG. 1 as it isproperly positioned on a patient.

FIG. 3 illustrates the first step in the method for determining the sizeof the device to be used on a patient according to this invention.

FIG. 4 shows another step in the method for determining the size of thedevice to be placed on a patient according to this invention.

FIG. 5 illustrates the positioning of a dimensional array on thetemplate device according to this invention.

FIG. 6 shows preferred dimensions of receptors V₂, V₃ and V₄ in thedimensional array.

FIGS. 7A-7C show a dimensional layout of a small, medium and largetemplate according to this invention.

FIG. 8 shows another embodiment of the present invention for attachmentto the torso of the patient.

FIGS. 9A and 9B show still another embodiment of the present inventionfor attachment to the torso of the patient.

FIGS. 10A and 10B show yet another embodiment of the present inventionfor attaching electrodes to the torso of the patient.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings, FIGS. 1 and 5 illustrate a template 10 inaccordance with a first embodiment of the invention. In this embodiment,an array of electrodeless receptors 22 are positioned at a predetermineddimensional array V₁ -V₆ on the template.

FIG. 1 illustrates the template 10 of the present invention forplacement on the chest of a patient. The template is formed of aflexible non-conducting sheet 11 which, in this non-limiting example,incorporates multiple conductor strips 12 for connection to a standardelectrocardiographic receiving unit. The non-conducting sheet 11includes conductor strips 12 which form end sensors or receptors 22which are positioned on the sheet and spaced relative to each other,whereby the receptors 22 are positioned in a specific size configurationappropriate for electrocardial recordings. Each strip 12 includes areceptor 22 at a first end portion adapted for electrical connectionwith the skin for receiving and transmitting electrical impulsesgenerated by the body. A second end of each strip 12 at the terminalconnector end 23 engages a common electrical connection or cablejunction (not shown) for connection with the electrocardiograph device(not shown).

When in use, an electrically conductive ink containing a biocompatibleadhesive gel is applied to the body contacting side of sheet 11 at eachreceptor 22 of connector 12 for adhesion to the skin of the patient forproviding electrical connection between each of the precordial ends andthe terminal end 23 connected to the proper receiving devices (notshown).

The adhesive gel coated area of the connector device includes at leastone release liner in releasable adhesive contact with the gel. Each ofthe conductor strips 12 are less than 10, and preferably less than 5,micrometers in thickness, whereby the flexibility of the connector andadhesion of the gel surface to the skin are substantially enhanced.

FIG. 1 shows the connector array (V₁, V₂, V₃, V₄, V₅, and V₆) on theflexible sheet 11 which is designed to adhere to a human torso so thatthe receptors 22 are located below the sternum, over the epigastricregion of the abdomen and near the centerline of the torso. The flexiblesheet 11 can be substantially transparent and includes an opening in theproximate center which is intended to span the upper portion of thesternum of the patient. The sheet may include indicia adjacent to or oneach of the conductor strips to facilitate correct placement of thereceptors on the precordial areas of the human torso.

FIG. 2 illustrates the position of the electro-dermal connector device10 as it is properly positioned upon a patient. The connector device 10is generally attached by adhering the precordial receptors. Thereceptors at V₁ and V₂ are attached approximately on opposite sides ofthe sternum at the fourth intercostal space. The receptors at V₃ and V₄are attached over the ribs, with V₃ positioned approximately equidistantbetween V₂ and V₄. The receptors at V₅ and V₆ are placed at the side ofthe torso so that V₅ is substantially midway between V₄ and V₆. Forsmall sizes the distance between V₄ and V₆ is on the average of 3.5inches, for medium sizes 5.0 inches and for large sizes 7 inches. Ofcourse, these measurements have a degree of tolerance, e.g., ±1.0 inch,to provide a range within which the connector device operateseffectively. It should also be appreciated that distances between any ofthe receptors that fall outside the ranges disclosed herein are stillconsidered to be within the scope of the invention as long as aneffective, easy to use connector device is provided in consonance withthe disclosed invention. The contour of the template 10 is configured toconform substantially to the shape of a human trunk.

In cross section a preferred laminate of the invention comprises thefollowing layers:

a) a flexible non-conductive film of polyethylene terphthalate;

b) catalyst layer in contact with silver ink;

c) a connector strip comprised of silver ink;

d) a dielectric layer in contact with silver ink;

e) a conductive hydrogel layer superimposed upon the silver ink layer;and

f) a flexible release liner as the top layer superimposed upon theconductive hydrogel.

The flexible non-conductive web or sheet 11 may be formed from anynon-conductive flexible natural or synthetic sheet material which iscapable of accepting a print. Generally any cellulosic material,polyester, polyolefin, polyvinyl chloride, nylon or mixtures thereofwould be suitable. Cotton, polypropylene, polyethylene can be usedbecause of cost. However, polyester is most preferred. The polymer sheetmaterial may be color coded for specific body areas or may contain anoutline and/or color markings to simplify attaching or positioning ofthe electro-dermal connector device. As mentioned earlier the device ofthis invention is designed to include the use by an untrained or trainedindividual. This device allows an untrained person including thepatients themselves to obtain highly reliable and repeatable ECGsignals.

The receptors 22 can be produced from any electrically conductivematerial, e.g., metals, conductive polymers, graphite, carbon fibers andthe like. Conductive materials such as gold, copper, silver, tin,aluminum, N-vinyl pyrrolidone and alloys or mixtures thereof may beused. The receptors can be made of metal foil or made from a conductivepaste of a metal in particle form in a suitable binder which is printedor silk screened onto the flexible non-conductive sheet. The connectivepolymer may be heat pressed or otherwise conventionally adhered to theweb or sheet.

Copper strips may be electrolessly deposited on the polymeric sheets ina range of thickness from about 0.25 to about 5 microns, more preferablyfrom 0.25 to 1.5 microns and most preferably 0.4 microns in thickness.

If desired, the exposed conductive strips may be partially coated with adielectric polymeric material so that only selective portions areexposed. Suitable dielectric coatings include polyesters, ethylene-vinylacetate copolymers, polyvinyl chloride and its copolymers, terpolymerssuch as acrylonitrile-butadiene styrene (ABS resins) and inter alia.

Preferable to copper, however, a metallic ink may be used, such as asilver ink commercially available and marketed by Dupont Chemical Corp.of Wilmington, Del. under the tradename Composition 9793.

One conductive adhesive hydrogel used is manufactured by PolyflexCircuits. Other suitable conductive adhesives are sold commercially byLec Tec Corporation of Eden Prairie, Minn. and by 3M Corporation of St.Paul, Minn. Although an adhesive hydrogel is preferred any commercialelectro-dermal adhesive would be operable. Preferably the area size ofthe hydrogel is between about 3 and 9 square centimeters.

The flexible release liner may be made from a suitable dielectric filmor coated paper which includes polyesters, olefinic polymers, polyvinylchloride and its copolymers, acrylic rubbers, ABS resin and the like.

In this embodiment the template 10 comprises at least six gel contactareas and is adapted for use in electrocardiography.

In accordance with the present invention, the template 10 is availablein various sizes. More specifically, by properly positioning thedimensional array V₁ -V₆, a template having three sizes (small, mediumand large) is sufficient to accommodate nearly any size adult person. Inpositioning the array, it has been found that the distance betweenconnectors V₁ to V₄ is generally consistent for all three sizes. Thedimensions between V₁, V₂, V₃ and V₄ have been developed to accommodatenearly all adults within tolerances acceptable for the resting ECG. Ithas also been found that body placement for connectors V₅ and V₆ varydepending on individual size. Although in this embodiment three sizesare disclosed, it will be appreciated that templates of different sizesare well within the scope of the invention.

FIG. 3 shows a method of determining the proper size. In this figure,the measurement M from the V₄ position to the V₆ position determines thesize of the device. This measurement can be determined by having thetechnician measure, such as by using his/her thumb and the middlefinger, the distance between the midclavicular line and midaxillary lineon the chest of the patient. This distance is then matched to a scaleprovided as shown in FIG. 4. The table below corresponds to theillustrated scale.

                  TABLE I                                                         ______________________________________                                        SIZE           V.sub.4 -V.sub.5                                                                      V.sub.5 -V.sub.6                                       ______________________________________                                        Small          1.75"   1.75"                                                  Medium         2.50"   2.50"                                                  Large          3.50"   3.50"                                                  ______________________________________                                    

Generally, the size of the vest is determined by the distance between V₄to V₆. That is, the distance between the midclavicular line and themidaxillary line on the patient. For a small or device the distancebetween V₄ and V₆ can range from about 2.5 to 4.5 inches, for the mediumvest the distance can range from about 4.0 to 6.0 inches, and for thelarge device the distance can range from about 6.0 to 8.0 inches.

In all sizes of the device of the invention, V₁, V₂, V₃ and V₄ aregenerally positioned the same. With reference to FIG. 5, the center ofV₁ is located on a point generally about 2.00 inches±0.56 inches fromthe center of V₂ approximately on the 270 (90) degree radial from thecenter of V₂ wherein the radial is measured with zero degrees from thetop of V₂. The center of V₄ is located on a point generally 3.5inches±1.00 inch from the center of V₂ approximately on the 125 (235)degree radial from the center of V₂. The center of V₃ is in line with V₂and V₄ and is located on a point substantially between the center of V₂and the center of V₄. FIG. 6 shows preferred dimensions for V₂, V₃ andV₄.

A typical dimensional layout for V₅ and V₆ relative to V₄ is shown inFIGS. 7A, 7B and 7C, and is as follows:

                  TABLE II                                                        ______________________________________                                        SIZE           V.sub.4 -V.sub.5                                                                      V.sub.5 -V.sub.6                                       ______________________________________                                        Small          1.75"   1.75"                                                  Medium         2.50"   2.50"                                                  Large          3.50"   3.50"                                                  ______________________________________                                    

The distance between V₁ and V₂ is 2.00 inches, the distance betweensternum centerline and V₄ along a horizontal line is 3.85 inches and thedistance between V₂ and V₄ along a vertical line is 2.00 inches,although this vertical distance could be up to 3.50 inches withoutconsiderably altering the effectiveness of the device. In addition, V₃is located on a diagonal line between V₂ and V₄ and is equidistant fromV₂ and V₄.

As discussed above, the connector device can be sized to accommodatepractically any size adult person. Even if the person is smaller thanthe "small" size device, a connector device of the small (or even mediumor large) size can be used by folding the flexible sheet 11 over onitself to reduce the distances between the connector arrays asappropriate.

As will be appreciated, the embodiment shown in FIGS. 1-7C provides aplurality of connectors arranged in a predetermined dimensional array V₁-V₆ on the flexible sheet. In providing alternative embodiments of thepresent invention, the dimensional array on the flexible sheet isutilized, and the specific size configuration of the dimensional array,or layout, on the flexible sheet is determined in the same manner asdescribed above. In the following embodiments, however, the connectors(and attendant ends sensors 22, conductor strips 12 and terminalconnectors ends 23) are removed, and the predetermined dimensional arrayis used in alternative ways to provide a consistent electrocardialrecording.

In the embodiment shown in FIG. 8, a flexible sheet 30, which iscomparable to the flexible sheet 11, is provided with a plurality ofspaced openings O₁ -O₆, or cutouts, for positioning electrodes on thepatient's chest. The openings O₁ -O₆ are positioned in the predetermineddimensional array V₁ -V₆ in the same manner as described above toaccommodate almost any size adult person.

In use, the flexible sheet is placed on the patient's chest, and servesas a template to position an electrode within each opening.

FIGS. 9A and 9B show another embodiment in which flexible sheet 30 isprovided with a plurality of conventional tab electrodes E₁ -E₆ andsmall openings O₁ -O₆ proximate to the electrodes.

The electrodes E₁ -E₆ are positioned in a predetermined dimensionalarray V₁ -V₆ in the same manner as the sensors to accommodate almost anysize adult person. As best seen in FIG. 9B, top sides of the tabelectrodes are affixed to the flexible sheet and the small openings O₁-O₆ expose electrical tabs 32 for attaching lead wire clips 34.

In another embodiment, individual electrodes E₁ -E₆ are detachablyaffixed to the flexible sheet 30 as shown in FIG. 10A. In thisarrangement, top sides of the electrodes are lightly affixed to theflexible sheet in the same predetermined dimensional array disclosedabove.

In use, the flexible sheet and electrodes are placed on the patient'schest. The flexible sheet is then peeled away, leaving the individualelectrodes properly located on the chest (see FIG. 10B).

Although not shown, it will be appreciated that the flexible sheet 30shown in FIGS. 8, 9A, 9B and 10A can be provided with an opening in theproximate center as shown in FIG. 1 to assist in positioning the sheeton the patient's chest.

Although specific embodiments of the present invention have beendescribed above in detail, it will be understood that this descriptionis merely for purposes of illustration. Various modifications of andequivalent structures corresponding to the disclosed aspects of thepreferred embodiments in addition to those described above may be madeby those skilled in the art without departing from the spirit of thepresent invention which is defined in the following claims, the scope ofwhich is to be accorded the broadest interpretation so as to encompasssuch modifications and equivalent structures.

What is claimed is:
 1. An electro-dermal sensor positioning devicecomprising a substrate having a fixed array V₁ -V₆ of receptor positionspositioned in a specific size configuration appropriate forelectrocardiographic recording, with said receptor positions V₁, V₂, V₃and V₄ positioned at predetermined fixed locations on said sheet andsaid receptor positions V₅ and V₆ positioned at predetermined fixedlocations on said substrate which vary dependent on patient size,wherein:the distance between V₁ and V₂ is approximately 1.50 to 2.50inches and the distance between V₂ and V₄ is approximately 2.50 to 4.50inches, with V₃ located substantially midway between V₂ and V₄, and V₅being substantially equidistant between V₄ and V₆.
 2. The device ofclaim 1, wherein the distance between V₄ and V₅ and between V₅ and V₆ isabout 1.75 inches.
 3. The device of claim 1, wherein the distancebetween V₄ and V₅ and between V₅ and V₆ is about 2.5 inches.
 4. Thedevice of claim 1, wherein the distance between V₄ and V₅ and between V₅and V₆ is about 3.5 inches.
 5. The device of claim 1, wherein V₁ islocated approximately 1.50 to 2.50 inches in radius on about a 270degree radial from the center of V₂.
 6. The device of claim 1, whereinV₃ is located on about a 125 degree radial from the center of V₂.
 7. Thedevice of claim 1, wherein V₄ is located on about a 125 degree radialfrom the center of V₂.
 8. A device according to claim 1, wherein thedistance between V₂ and V₄ ranges between 2 and 4.5 inches.
 9. A deviceaccording to claim 1, wherein a vertical distance between V₂ and V₄ isapproximately 2.5 to 3.5 inches.
 10. A positioning device of claim 1,wherein said substrate is disposable.
 11. The device of claim 1, whereinV₅ and V₆ can be positioned at three different locations on thesubstrate.
 12. The device of claim 1, wherein said substrate is selectedfrom nonconductive flexible natural or synthetic material.
 13. Thedevice of claim 12, wherein said substrate is selected from cellulosicmaterials, polyesters, polyolefins, polyvinyl chloride or nylon.
 14. Thedevice of claim 13, wherein said cellulosic material is cotton or paper.15. The device of claim 13, wherein said polyester is polyethyleneterphthalate.
 16. A process of forming an electro-dermal sensorpositioning device for electrocardiographic recording, comprising thesteps of:providing a substrate with a fixed array V₁ -V₆ of receptorpositions positioned in a specific size configuration appropriate forelectrocardiographic recording; positioning receptor positions V₁, V₂,V₃ and V₄ at predetermined locations on the substrate; positioningreceptor positions V₅ and V₆ at fixed locations on the substrate whichvary dependent on patient size; and positioning the receptor positionsV₁ -V₆ such that the distance between V₁ and V₂ is approximately 1.50 to2.50 inches, and the distance between V₂ and V₄ is approximately 2.50 to4.50 inches, with V₃ located substantially midway between V₂ and V₄, andV₅ substantially equidistant between V₄ and V₆.
 17. A process accordingto claim 16, further comprising the step of positioning receptorpositions V₅ and V₆ based on a distance between a midclavicular line anda midaxillary line on the chest of the patient.
 18. A process accordingto claim 16, further comprising the step of positioning receptorpositions V₁ and V₂ to be approximately on either side of the sternum atthe fourth intercostal space and positioning array V₃ to beapproximately midway between V₂ and V₄.
 19. A process according to claim16, wherein the distance between V₄ and V₅ and between V₅ and V₆ for asmall size is about 1.75 inches, for a medium size is about 2.5 inches,and for a large size is about 3.5 inches.
 20. A process according toclaim 16, wherein V₁ is located approximately between 1.50-2.50 inchesin radius on about a 270 degree radial from the center of V₂.
 21. Aprocess according to claim 16, wherein V₃ is located on about a 125degree radial from the center of V₂.
 22. A process according to claim16, wherein V₄ is located on about a 125 degree radial from the centerof V₂.
 23. A process according to claim 16, further comprising the stepof providing a disposable substrate.
 24. The process of claim 16,wherein V₅ and V₆ can be positioned at three different locations on thesubstrate.
 25. A plurality of sensor positioning devices of differentsizes, with each device comprising:a substrate with a fixed array V₁ -V₆of receptor positions positioned in a specific size configurationappropriate for electrocardiographic recording, with the receptorpositions V₁, V₂, V₃ and V₄ positioned at substantially the samelocations on each said size, and receptor positions V₅ and V₆ positioneddifferently on each said size dependent upon the size of the patient.26. The devices of claim 25, wherein in each said device the distancebetween V₁ and V₂ is approximately 1.50 and 2.50 inches and the distancebetween V₂ and V₄ is approximately 2.50 and 4.50 inches, with V₃ locatedsubstantially midway between V₂ and V₄, and V₅ is substantiallyequidistant between V₄ and V₆.
 27. A device according to claim 26,wherein a vertical distance between V₂ and V₄ is approximately 2.0 to3.5 inches.
 28. The devices of claim 25, wherein three sizes of saiddevices are provided, with the distance between V₄ and V₅ and between V₅and V₆ for a small size being about 1.75 inches, for a medium size beingabout 2.5 inches, and for a large size being about 3.5 inches.
 29. Thedevices of claim 25, wherein in each said device V₁ is locatedapproximately between 1.50 and 2.50 inches in radius on about a 270degree radial from the center of V₂.
 30. The devices of claim 25,wherein in each said device V₃ is located on about a 125 degree radialfrom the center of V₂.
 31. The devices of claim 25, wherein in each saiddevice V₄ is located on about a 125 degree radial from the center of V₂.32. The device of claim 25, wherein said substrate is disposable.
 33. Anelectro-dermal sensor positioning device comprising a flexible substratehaving a fixed array V₁ -V₆ of receptor positions positioned in aspecific size configuration appropriate for electrocardiographicrecording, with said receptor positions V₁, V₂, V₃ and V₄ positioned atpredetermined fixed locations on said substrate and said receptorpositions V₅ and V₆ positioned at predetermined fixed locations on saidsubstrate which vary dependent on patient size, wherein:V₁ is locatedapproximately between 1.50 and 2.50 inches in radius on about a 270degree radial from the center of V₂.
 34. The device of claim 33, whereinsaid substrate is disposable.
 35. The device of claim 33, wherein saidsubstrate is selected from nonconductive flexible natural or syntheticmaterial.
 36. The device of claim 35, wherein said substrate is selectedfrom cellulosic materials, polyesters, polyolefins, polyvinyl chlorideor nylon.
 37. The device of claim 36, wherein said cellulosic materialis cotton or paper.
 38. The device of claim 36, wherein said polyesteris polyethylene terphthalate.
 39. A process of forming an electro-dermalsensor positioning device for electrocardiographic recording, comprisingthe steps of:providing a substrate with a fixed array V₁ -V₆ of receptorpositions positioned in a specific size configuration appropriate forelectrocardiographic recording; positioning receptor positions V₁, V₂,V₃ and V₄ at predetermined locations on the substrate; and positioningreceptor positions V₅ and V₆ at fixed locations on the sheet which varydependent on patient size, wherein V₁ is located approximately between1.50 and 2.50 inches in radius on about a 270 degree radial from thecenter of V₂.
 40. A process of claim 39, further comprising the step ofproviding a disposable substrate.
 41. A process of forming a pluralityof sensor positioning devices of different sizes, comprising the stepsof:providing a plurality of flexible substrates, each with a fixed arrayV₁ -V₆ of receptor positions positioned in a specific size configurationappropriate for electrocardiographic recording; positioning receptorpositions V₁, V₂, V₃ and V₄ at substantially the same locations on eachsize substrate; and positioning receptor positions V₅ and V₆ differentlyon each size substrate dependent upon the size of the patient.
 42. Aprocess according to claim 41, further comprising the step ofpositioning receptor positions V₁ -V₆ on each size substrate, such thatthe distance between V₁ and V₂ is 2.00 inches±0.56 inches and thedistance between V₂ and V₄ is 3.5 inches±1.00 inch, with V₃ locatedsubstantially midway between V₂ and V₄, and V₅ is substantiallyequidistant between V₄ and V₆.
 43. A process according to claim 41,wherein the receptor positions V₅ and V₆ are positioned at fixedlocations based on a measured distance between a midclavicular line anda midaxillary line on the chest of the patient, with the fixed locationsvarying for each size substrate.
 44. A process according to claim 41,further comprising the step of, on each size substrate, positioningreceptor positions V₁ and V₂ to be approximately on either side of thesternum at the fourth intercostal space and positioning V₃ to beapproximately midway between V₂ and V₄.
 45. A process according to claim41, wherein three electro-dermal sensor positioning devices are formed,with the distance between V₄ and V₆ and between V₅ and V₆ for a smallsize device being about 1.75 inches, for a medium size device beingabout 2.5 inches, and for a large size device being about 3.5 inches.46. A process according to claim 41, wherein V₁ on each size substrateis located 2.00 inches±0.56 inches in radius on about a 270 degreeradial from the center of V₂.
 47. A process according to claim 41,wherein V₃ and V₄ on each size substrate are located on about a 125degree radial from the center of V₂.
 48. A process of claim 41, furthercomprising the steps of providing a plurality of disposable substrates.